Samad and colleagues have neatly shown what we already know: children born into circumstances that are socially or materially marginal are less likely to be fully immunised.1 At age 9 months immunisation rates in the UK are high (> 95% fully immunised); the challenges posed by Samad et al's paper are the challenges associated with reaching that last small percentage of children. This is in the context of the UK healthcare system, which is universal and doesn't impose user charges. Samad et al have shown also that children who are unimmunised fall into two groups: those from disadvantaged backgrounds and those with mothers who were on average older and more educated.

The first barrier to overcome is the framing and labelling barrier; the term “hard to reach,” along with its semantic equivalents, is service-centric and an implicit admission of the system's failure, which in turn invites nihilism. “Hard to reach” thinking tends to transfer ownership of the problem to the victims of the problem, thereby taking the focus away from the role of the primary care system. A number of primary care approaches to immunisation have been shown to be effective.

Because poor populations tend to be more mobile, special attention needs to be paid to outreach and opportunistic immunisation. However, outreach on its own may not be sufficient: overall primary health care and social service capability are important too. Schuster et al found that home visiting alone was only partially effective and suggested that case managers may be more effective when they have resources to use to help overcome specific barriers.2 Opportunistic and outreach immunisation in turn need to be supported by a shared immunisation register.3

Opportunistic immunisation is equally important. It is likely that partial immunisation may be contributed to by missed opportunities, such as inappropriate delaying of immunisation after a hospital admission.3 It is important for hospitals to ensure that immunisations are given before discharge and that correct information is freely available as to what constitutes a contraindication. Likewise, immunisation update should be offered at all primary care contacts.

In order to address belief systems and conflicting information, tailored approaches to information are required for the unimmunised (for example, those of black Caribbean ethnicity).34

Finally, most importantly, the foundation for an effective immunisation system is the recognition that the most powerful and persistent barriers to timely immunisation are poverty and factors associated with poverty.3 In order to engage successfully with socially marginalised communities, and the health problems that typically occur in such communities, primary care needs to include in its remit intersectoral approaches to addressing poverty. Along with this, primary care needs to be underpinned by a community development approach which defines health in the context of social factors such as housing and the economy, acknowledges that health improvements do not necessarily start with health services, focuses on community wants, and takes a bottom-up approach.5